Power has been fully restored across India and an investigation launched after 620 million people were left without electricity in the biggest blackout in history.
The country's northern, eastern and northeastern grids crashed one after the other on Tuesday, cutting power supplies to half of the country.
The outages affected dozens of states stretching from Rajasthan to the Himalayas and Assam, sparking chaos on the railways and roads, forcing hospitals and businesses to rely on back-up generators, as well as leaving half of the country's 1.2 billion population sweltering in the heat.
It was the second massive outage in as many days, coming just after the country had recovered from Monday's failure of the northern grid, which plunged 370 million people into darkness.
The Confederation of Indian Industry said the two outages cost businesses hundreds of millions of dollars, although they did not affect the financial centre of Mumbai and the global outsourcing powerhouses of Bangalore and Hyderabad in the south.
The group joined calls for a widespread reform of India's power sector, which has been unable to cope with the soaring demand for electricity as the nation's economy expands.
India's newly-appointed power minister Veerappa Moily told reporters that by Wednesday morning power had been fully restored across the country and refrained from pointing the finger at individual states.
He cautioned that there would be no quick solution to the power crisis, saying the government was looking at immediate and longer term measures to address the issue.
His predecessor Sushil Kumar Shinde on Tuesday blamed areas for drawing more than their allotted share of electricity that may have led to the major system failure.
Some analysts dismissed this explanation, arguing the power grids would fail all the time if this was the case.
